Device for the picking and feeding of sheets from a ream

Abstract

A device 100 for the feeding of sheets 14 from a ream 18, with a main rotating, feeding roller 27; a tray 13 containing the ream 18; and an auxiliary roller 130 arranged adjacent to the feeding roller 27, wherein the tray 13 is suitable for moving cyclically to bring the ream 18 into contact with the feeding roller 27, so that the latter picks one at a time the sheets 14 from the ream 18 and feeds them along a path 131; and wherein the auxiliary roller 130 is adapted for rotating in contact with the sheets 14 picked by the feeding roller 27, but without pulling them and in the direction opposite their feeding direction, the object being that of opposing the picking of double sheets from the ream 18. The device 100 is provided with an improvement consisting of a cap 141 capable of moving in sync with the cyclical motion of the tray 13 with respect to the main feeding roller 27, so as to prevent, by coming between the auxiliary roller 130 and the sheets 14, any contact between them, at least during the motion of the tray 13. In this way, the front edges 140 of the sheets 14 can access the path 131 without running the risk of being crumpled and/or damaged by the auxiliary roller 130 with its rotation and, accordingly, of compromising the proper feeding of the sheets 14 from the ream 18.

What we claim is:  
     
       1. A device for picking one at a time a plurality of sheets from a ream and feeding them along a path, said sheets being reciprocally aligned in said ream along respective front edges, comprising: 
       a rotating main feeding roller;  
       a tray in which said ream is accommodated, said tray being normally disposed at a distance from said main feeding roller, and being provided for moving in such a way as to cyclically bring said ream into contact with said main feeding roller in order to separate said sheets one at a time from said ream and to feed them along said path in a feeding direction conforming to the direction of rotation of said main feeding roller, said sheets coming into said path with the respective front edges;  
       at least one auxiliary roller arranged parallel and adjacent to said main feeding roller, said auxiliary roller being provided for cooperating, by rotating according to a direction of rotation opposite to said feeding direction, in contact with said sheets to permit their correct separation from the ream, in particular without the feeding of double sheets occurring; and  
       protecting means capable of preventing any contact between the front edges of said sheets and said auxiliary roller during the motion of said tray to bring cyclically said ream into contact with said main roller, so as to protect said front edges from any damage produced by contact thereof with said auxiliary roller.  
     
     
       2. Device according to claim  1 , wherein said front edges are provided for following in the two directions a predetermined operating path, along which said auxiliary roller is arranged, during the motion of the tray to bring the ream near to or away from said main feeding roller, and wherein said protecting means are capable of operating in synchronization with said motion of the tray to keep said front edges constantly separate from said auxiliary roller. 
     
     
       3. Device according to claim  1 , wherein said auxiliary roller includes a plurality of refusing rollers staggered along said auxiliary roller with respect to corresponding feeding elements of said main feeding roller, said device further comprising: 
       regulating means provided for manually regulating the interference in the radial direction between said refusing rollers and said feeding elements; and  
       elastic means associated with said refusing rollers to permit the latter to move resiliently with respect to said feeding elements so as to adapt said interference in relation to the rigidity of the sheets that are being fed.  
     
     
       4. Device according to claim  2 , wherein said protecting means comprise a covering member arranged adjacent to said auxiliary roller, said covering member being capable of moving, with respect to the latter, in such a way as to cover a portion of said auxiliary roller facing said operating path, during the approach motion of said tray to said main feeding roller, and in such a way as to uncover said portion, during the withdrawal motion of said tray from said main feeding roller. 
     
     
       5. Device according to claim  4 , wherein said auxiliary roller is constantly connected in rotation with the motion of said tray, and is therefore liable to invert its direction of rotation during said motion, and wherein said covering member consists of a cap mounted rotatingly, but with a certain friction, on a shaft of said auxiliary roller, said cap being provided for rotating about said shaft between two angular end positions defined by two abutments against which said cap stops, 
       whereby, when said auxiliary roller rotates in accordance with a first direction of rotation corresponding to the approaching of said tray to said main feeding roller, said cap is consequently dragged into rotation through friction by said shaft until it stops against a first of said abutments, so as to cover said portion; and  
       whereby, when said auxiliary roller rotates in accordance with a second direction of rotation, opposite the first, corresponding to the withdrawing of said tray from said main feeding roller, said cap is consequently dragged through friction into rotation by said shaft in the opposite direction to before until it stops against the second of said abutments, so as to uncover said portion.  
     
     
       6. Device according to claim  5 , wherein said auxiliary roller comprises a plurality of refusing rollers mounted on said shaft, and said cap is shaped in such a way as to partially cover both at the sides and along the cylindrical periphery each of said refusing rollers.